What is Reed Sensor

A Reed Sensor's core is a reed switch, and the reed switch is firmly encapsulated into a plastic or metal housing for better mechanical protection. A reed switch is a special kind of electrical switch consists of two ferromagnetic reeds or blades which are sealed inside a glass tube, filled with inert gas. The reeds or blades are usually separated with an airgap (NC type) which will be in contact under the influence of a magnetic field. Or the reeds or blades are usually in contact (NO type) which will be separated under the influence of a magnetic field.

Generally speaking, there are three types of reed sensors: Below is the introduction of these three types of reed sensors.

Normally Open Reed Sensors

In standby status, the two reeds in this NO reed sensor which are made from ferrous material such as nickel-iron alloy are separated, device with normally open reed sensor is powered off unless the magnet is applied. When a magnet is moved close to the switch, one of the reeds moves towards the other to form a contact status, and hence to complete the circuit. Move the magnet away, the reed returns to its original position so as to break the circuit.

Normally Closed Reed Sensors

In contrast, normally closed reed sensor is in closed circuit as the default. When the magnet is applied, the reed switch disconnects and breaks the circuit off. Electric flows through a normally closed reed sensor until the magnet forces the two reeds apart.

Changeover Reed Sensors

Changeover reed sensor has three contact points. In this sensor, the current flows along with a common lead which can be switched between two contacts.

The common lead is in contact position with one reed in default status. If a magnet is introduced, the common lead will be switched to the other contact. When the magnetic field is removed, the common lead reverts back to its original position.

Applications of Reed Sensors

Reed sensors provide a very simple and controllable mechanism for safely opening and closing circuits. As a result, they are commonly seen in many industries. A frequently used application is proximity and position sensing.

Over the years by working with different customers, BST is proud to serve the following industries with high-quality reed sensors:

• White goods. Reed sensors operate well in appliances that needs to detect on/off status, such as dishwashers,  refrigerators and coffee machine.

• Industry automation. Reed sensors have many applications in production. For example: cylinder pistons ,conveyor belts and automated factory machinery all use reed sensors to detect limits and facilitate on/off functionality.

• Electronics. Reed sensors are important parts for opening and closing system of automatic doors. They are served as proximity sensors for security devices used on doors and windows.

• Fitness equipment. Reed sensors can be used in a variety of recreational and fitness equipment. For example, reed sensors serve as speed sensors in bicycle wheels and treadmills.

• Off-Road Vehicle. A cement truck's tank needs to rotates to prevent cement from setting, the reed sensor attached to the tank will continuously send signals to tell the driver the tank is rotating. Once the tank stops rotating, the reed sensor will release a stop signal.

Reed Sensors from BST

BST, locates in China, specializes in providing standard and custom reed sensor for different industrial and commercial applications. Each sensor comes in several options to best match the applications. Some of our options for custom sensors include:

• Housings. Plastic and metal housing  are available, and flange mount and cylindrical housing are also available.

• Electrical parameters. Different cable and connectors are available to meet customer's input and output requirements.

• Environmental protections. Anti-shock mechanisms and ingression level from IP54 to IP69 are optional.

BST has been producing high-quality sensors for more than 20 years. We value customer's requirement and work closely with customers for the best and most optimized sensor solution. Contact us to learn more about our capabilities or request a quote to place your order from our sensors.